Computing-machine.



.L T. JACKSON COMPUTING MAHI APPLICATION FILED JULY 11, 1907.

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To all whom it may concern' umrnn A sri-mns matr .TOSHU'A- TERRY JACKSON, OF TEXARKANATEXAS.

COMPUTING-Meerman.

i Specification of Letters Patent.

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Application filed July 11,'190v7f Serial No. 333,133.

, to provide a combined adding and subtracting machine that is simple in construction,

y, easily understood, and, having Jfew parts, will not readily get out'oi order, i the simplicity of its construction rendering it capale of being economically manufactured S0 that it can be sold for a comparatively small price; to supply a computinggl machine havmg such form and dimensions that it can be readily carried from place to place, and when` desired may be larranged in juxtaposition with the columns of' iigures on a sheet or page, thus facilitating the Work of the -accountant to a marked degree; andto furnish-a combmed adding and subtracting `device in .which the lmanual movements for the diiferent computations will'be identical, thus i .avoiding the tendency to confusion which will result when the required motions are reversed, as is usual in devices of this class. Further objects of my' invention are to provide means for readily differentiating the roups or vplaces for the figures, by means 1ndependent of their relativeposition; and to supply mechanism for preventing the displacement of the indicating members when once set, avoiding errors from the momentum imparted .to said members, and to lock the latter in 'position so that-theywill'remain immovable under Ordinar manipulations loi' the device, and es ecial y when reversing the instrument, 'w ich is,v required when changing from one form of computationto another.

l'accomplish the. above and other important results by the employment of anl apparatus which consists, generally speaking, of

a iat rectangular case, in which are arranged in parallel a series of alternatelyfixed and movable bars, the fixed bars numerals 1 to 9 impressedupon'their upper jconvenient A exposed .betweenjtne margins ol the casing 1s faces in, yregular columns, thus constituta key board, which. visible in an-inter- 1n v5Av in the, casing, and the sliding bars having spaced. abutments corresponding'with `the said numerals, by means' of which',` the said,

barscan be reciproc'ated through'the medium of the pencil or stylus point in either direc-' tion, suitable sight holes beingl provided to permit inspection 'oilindi'cfating iigure's which are carried by said sliding bars. y

or columns are read downward, instead of from left to'right, the slidable' bars representing the orders or periods, beginning with thelowest slide which is regarded as units,y or when considered decimally would be regarded ashundredths. As an aid in' the mnemonic process the slid'ablel members are given contrasting colors, each group, or eriod, having theV same'y color, the-right and .left hand portions, however, being furnished withdiiierent depths of color;` thus theplefti hand hall'of each bar has a dark coloranti the right hand halla lighter tint, thus little mental effort being required todiilerentiate the two portions, and' in short time the 1 The periods' mental kprocess will become purely auto;

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in ythe accompanying' drawing, which forms a part of this'speeificat1on;fF1gure 1 is .a plan View' of my improved computing 'machine; showing the side arranged for adding; lFig. 2 is a plan view of the reverseside, usedin subtraction, a portion of the casing being broken away todisclose the method of construction; -Fig.y 3 is a'sectional. view o n the line 3- 3 'ci Fig'.` 1; Fig. 4 is a erspective view of' one of th'e'iined bars, and lgs. 5 and 6 are rear .and front views, reepectively,. of one of the, ,slidablejbars- Refer-ringl to the drawing in detail, the numeral characters 10, 10a, indicate the side members andl 11y the end pieces of a rectangular frame,l oblong in shape andprovided with a casingorside plat-esl?, which'extend from 'the ends ,to approximately one third .the

length of said frame,lthus leavingan interval in thecentei equal to aboutone third the areak of the fra-,meu'ncove're'd. This interval is occupied by a series of rectangular bars 13 placed parallel.andl spaced apart at'equal 1ntervals.,. V'lfhese bars are somewhat longer thantjhe space, between the casing plates 12, andtlieir ends afrejreceived between eac h pair of said yplates andfsecu'red in positioniu any i That nertion ol each bar reduced in vertical diameter and supplied with spaced characters consisting of the digits from 1 to 9, so placed on the bars 13 that the said characters will fall in vertical columns when the parts are assembled and when so arranged constitute guides for prop-v erlylocat-ing the pencil or stylus during the com uting processes, and hereinafter termed the eyboard. T he rear face of each bar 13 is furnished with a longitudinal U shaped channel or groove 14 and the front face is supplied with a recess 15 to permit of ade quate movement of a flat detent spring 16 secured at one end to the said bar and near the other is bent at an angle to form a projection 17 adapted to engage notches in the sliding members hereinafter described. Near one end of the reduced portion of each bar is a semi circular sight notch 18 formed by cutting away a portion of the u )per rear corner of the bar. ln theintervals etween the said` fixed bars 13 and the casing and the bars themselves, are located slidable members 19 of such length .that when one end abuts against either end piece 11 of the frame, the other will vextend beyond the opening between the casing plates. The anterior margin of each slide 19 is beveled to forni an anguiar ridge or projection 2O adapted to be received in the rear groove 14 of the adjacent fixed bar 13. The frame member 10 also has a V-shaped groove 141a formed upon its inner surface to receive the projection of the adjacent slide and its rear upper corner has a sight notch 18a corresponding with the notches 18 in the iixed bars 13. The rear margins of the slides are provided with spaced notches 21 with which the projections 17 of the detent springs 16 yieldingly engage as the slides are reciprocated. The upper and lower faces of the said slides are provided with spaced lugs or flanges 22 which serve as abutments against which the stylus impinges to operate the slide in either direction. Upon the upper and lower surfaces of the `projecting angular ridge 2O are impressed the ordinals 0 to 9. The ordinals 23 upon the upper surface are arranged from' left to right, beginning at-the extreme left, and the characters 24 upon. the under surface are placed in the same order, but inverted when the slide is viewed as a whole, as shown in Fig. 6; when the slide is reversed the latter figures appearing right side up but reversed as to order, diminishing from left to right, which makes them available for the operation of subtraction7 those upon the superior aspect being properly arranged for addition when that side is up ermost.

The key-board is alike upon both sides of the device and consequent y the manipulation will be the same for either adding or subtracting.

The slide bars 19 represent the places or groups of figures; thus the lowest bar repre- `sents units, the second tens and so on, up to the highest, which in the illustration is carried to hundreds of millions as shown in Figs.

1 and 2, by the designations placed to tieA right of the key board. lt is often convenient to consider the first two places as a decimal, especially in computing U. S. money, and to aid in locatin the places under this system of notation t .e proper designations are placed to the left of the key board. To further assist the eye in determining the columns or places the first two slides, representing cents are colored upon the left in unison, in the instance given being designated as green, indicated by a. The units tens and hundreds of dollars are colored purple b, the thousands slides are tinted green, returning again to purple in the millions of dollars. The opposite ortions extending from the median line to t ie extreme end, are supplied with a contrasting color, lighter in tint. rlhus the decimal placers are colored white c, upon the right and the units, hundreds and thousands a light blue d, returning to white in the next period, and so on.

It will be seen that the arrangement oi' slides shown and illustrated will permitI the ordinals imprinted upon the inclined surfaces of the projection 20 to be readily seen through the notches 18, which form the sight openings, as the iigures are brought successively opposite to said openings during the sliding of the members 19 in the manner to be described.

The manipulation of the appliance is as follows for the rocess of addition: Supposing the slides to e all carried to the right until 0 appears at every sight notch and it is desired to add 6 dollars, 30 cents and 2 cents, a pencil or stylus is placed upon the slide corresponding with dol ars against that lug which is opposite the figure 6 of the adjacent fixed bar 13 and the slide carried thereby to the left until the pencil strikes the margin of the casing plate which forms a sto therefor; the numeral 6 will then appear in t e corresponding notch. The same procedure is repeated for 30 cents, the stylus or pencil being placed' upon the second slide, and when this has been moved the units slide is moved two steps in the same manner, and 632 will be read throu h the notches. If, now, it is desired to ad 8 units, the pencil is placed at 8 on the first slide but as the color has changed at the point designated, being 4no longer green, but white, this is a signal to the operator to move the slide to the right until the stylus strikes the right hand plate, and thismovement to the right is always the slide of next higher denomination one step to the left, to carry one to that denomination. Thus in the instance given (Fig. 1) the lug at 8 is to be carried to the right, and the next slide moved one step to the left with the result that 640 will then appear at the to be followed by moving reverse the lateral movement for the opposite colors, and Whenever there is a right hand movement there must be a corresponding carrying to the next column. It will frequently happen that all the slides will show a light color when it is necessary to carry l t'o that column. In such case the same rule holds, the pencil is moved .to the right until it strikes the stop plate, and then is carried to the next higher denomination, and if the 1 of that slide is also White the movement is also to the right and so on until a slide is reached in which l appears in a dark or left hand color, when the movement is again to the left. 'Considering the left' hand movements as positive, and the right hand ones as negative, We may formulate the following rule: When the stylus is placed upon a dark color the movement must be positivefaiid when upon a light color the movementlmust he negative, 'every vnegative movement beingA a reminder to .carry to the vnext higher denomination.

It is obvious that many changes may be madein the details v0iE construction of my invention as herein disclosed without depart-A ing from the spirit and scope thereof and I do not wish, therefore, to be limited to the pre- ,cise form of the device illustrated.

' Having thus described my invention, what I claim as new, is:

l. In a computing device, a suitable casing having openings therein, a series of numeral hearing hars fixed in said casing, each oi" said bars having a single opening in its face and provided With a longitudinal groovel upon one side, a series ol numeral hearing .bars slidably mounted in said casing and ar ranged alternately with said fixed bars, each of said slidable bars having a ridge engaging said groove in the 'adjacent fixed bar, the

numerals on said slidable bars being posi tioned so as to exposed only at the openings in the fixed bars, means for moving the slidable bars, and means for limiting the movement of said bars.

2. in a computing device, a suitable cas.-

ing, having openings therein, a series of numeial 1nearing lbars iixed in said casing, each of said bars having an opening in its face, and provided withv a longitudinal groove upon one side, a series of bars slidahly mounted in said casing, each of said bars having a longitudinal. ridge engaging the groove in the adjacent iixed har, and provided with. a series of numerals and a series of spaced'abutnients upon opposite faces, and the numei als so arranged relative to the fixed bars as to be exposed Aonly at the open ings in said hars, and means for limiting the movements of the slidalole hars.

3. In a computing device, a suitable casing having'openings therein, a series of bars fixed in said vcasing and hearing numerals on their opposite faces, each of said 'bars having a longitudinal groove coextensive with the har, and provided with a rounded notch and also furnished. with a recess, a spring detent secured in said recess, a series of bars slidahle in said casing Vand hearing numerals upon their 'opposite taces, said numerals so arranged as to be exposed at the notches in the iixedhars, said slidahle bars havingv spaced notches in one edge adapted to be engaged by said spring-'g detents, and spaced ahutinents arranged upon. opposite sides of 

